Process of heating cement-kilns by producer-gas and apparatus therefor.



No. 887,316. PATENTED MAY 12, 1908. H. L. DCHERTY. PROCESS CP HEATINGCEMENT KILNS BY PRODUCER GAS AND APPARATUS THEREFCR.

APPLICATION FILED DEC.6.1905.

. cubic foot of illuminating gas.

` and air.

vducer gas contains so large an amount of srarasrarnnTQWW/E# E HENRY L.nonnn'rr', or MAn1soN",'wiscoNsn\I-, -iissieuoa 'ro coiiBUsrioN-UriLirins con PANY, or Nvnw- Yoann. Y., A conrona'rion or lNEW Yonx.rnocnss or rma'rIrisenMnN'r-xinns er nnonncnn-sasann arri-inertie'rmianron Specication of' Letters Eats-nt.

- resented insg raices. f 'Application mes neembr c,- i'aes.seriaiiiojzcdaar.

No. sanare.

remaining variables aiiecting the flame temperature to be considered,are .the temperatures ofthe entering gas and air respectively. ,lnfanapplication filed .November 14th,

To all whom it may concern:

vBe it known that,-HnNnY L. Donnn'rr, a citizen of the United States,and resident ot Madison, in the county of Dane and State oi i Wisconsin,have invented acertain new and useful Process of Heating Cement-Kilns byProducer-Gas and Apparatus Therefor, of which the following is aspecification.

This invention relates to a method of burning producergas in itslapplication as a heating agent to the manufacture of Portland cementinrotary kilns and to apparatus adapted therefor.- l

Generally' speaking, producerl gas has a lonr calorific value; a cubicfoot of ordinary producer gas containing only about {i0- toi; theheating value of a cubic foot of methane and only about to 2, theheating value ot a Burning in tree air, a producer gas name has amaximum temperature of perhaps 2200O F., while .ordinarily it has atemperature much below that noint, rarely reaching or exceedinL-fg2000?..- For this reason thenumerous e orts toutilize producer gas intheburning OPortland cement, in which very high temessarily has beencooled before using are obperatures are required, has not resulted suc-yvious.` u cessfullyin many cases. A minimum tem-i My invention consistsin process of pre; perature of perhaps 2400o F. in the cement materialisrequired toinstitute c'linkering, while in practice a clinkering iiamemust be several hundred degrees higher,- ii burning in the usual. typeof rotary kiln,fto insure` this temperature in said material. `Prof haveshown and claimedapparatus by which combustion.- rl`he present inventionconcerns itself with a method of and means for vpreheating the gassupplied to the kiln.

of low thermal value. -Blue water gas, for instance, `being developedvby an intermittent process, cannot be'introduced into the kiln in auniform stream or current directly from the generator whence a gasreceiver or holder intermediatethegenerator and the kiln is needed.Storage oi. the gaslin this .manner results' in reducing vitstemperature practically to thatl of the circumambient airidirectly froma gas producer, prior to its entry nitrogen, acting as a diluent, thatthe proper flame temperature .for cement burning .is not easily reached.NoA method of enriching producer gas heretofore proposed, has beensuiiiciently economical to permit of a practical application. Y

rlhe temperature developed by. a mixture of combustible gas and airdepends upon the thermal value of the .combustible compos nents'of thegas, on the nature of the diluent components present, on the quantity ciair' or other supporter of combustion employed' and on the temperatureof the mingling gasy burned in' passages separate from those wherein theremainder of the gas travels; orl

. direct iired with oil, coal, coke or other fuel. Apparatus suitable`for carrying vout my processis illustrated diagrammatically in theaccompanying drawings, in which vvFigure l shows a gas producer; an endelevation of a cement kiln and a sectional' `iew of a heating stove, thelatter being depicted in As producer 4gas cannot be enriched,pracsection of said stove.

tically', for cement burning, as inherently nitrogen must bepresent as adiluent in producerA gas, and as the air supplied for. comof the termWell known in the art, comprisbusti'on is susceptible of easyregulation,.the ing an inclined barrel of considerable length Whileespeciallyy suited vfor preheating producer gas, myin-V vention may alsolie-employed in preheating vother combustible gases, particularly .thoseyThe advantages of preheating gas which neci into the kiln, through aheating stove, Which is maintained ata high tem erature by. the.-cornbustion of aportion oit e gas, suitably the gas may beheatedin afurnace, which is a conventional way, so that its functions mayVbefclearly comprehended. Fig.. 2v is a cross ln the drawings, l is theendrview or dis. charge end of a cement. kiln; said kiln being .1905,bearing the Serialhlumber 287,217, -l

,the air supplied'to the kiln is. heated to the requisite degree of`preheat for effective heating combustible gas to such a degree f that aflame having a temperature-of iro'rnr-y 26000 F. to approximately3000".'F. is gener-'- atedinthe kiln.. S eciiically myprocess consistsin passing the -otcombustible gas taken With a stack at the upper endand a hood at thelower end, 2 is the 4inlet for the gas through saidhood intol the kiln.

3 dlagrammatically illustrates a gasproducer;

4 is an outlet pipe or conduit for conveying the gas to a stove 5. Thelatter is constructed with a flue 6 in its u per part, throu h which thegas travelsI andp is heated, and t` e combustion chamber 7 in its lowerpart, in which the fuel employed is burned.

At 8 is shown a number of ports through which gas may discharge into thecombustion chamber 7. Air is admitted through the door or chamber 9.

10 is the stack connected to said combus- .-tion chamber, whereby theproducts of com- .after-haying put th k1ln througlh port 2. v Air isadmitted through' quired a 3000@ F.

lbustionare removed from the chamber 7, after having performed usefulWork -in heatin f the producer gas in theflue 6. l

4 n operating thls apparatus, itis necessary e gas producer into propercondition for gasification, to build a wood fire in the kiln l'and inthe chamber 7./ Gas..

is then passed through the Hue 6 and linto the the horses oe shapedportll, andthe miX- ture of gas and air, ignited by the Wood fire in thekiln, burns with a long Hameof low temperature characteristic ofordinary producer' as.l The ports 8 are thereuponopened, air

`oor 9, whereby eing admitted through the the chamber 7 becomes filledwith flame, thereby heating the Walls of the flue 6 toa marked degree.The. gas passing' through the ue 6 being heated to a Vtemperature higherthan its initial temperature, commences to burnin the kiln with a brightand clear flame. As the Walls of the flue '6 grow hotter, the creases intemperature, until finally it `will be observed that the :flame in thekiln 1 has actemperature of from 2600 F. to By admitting heated insteadof cold air through the port 11, the temperature of .the :dame isaugmented.

The gas producer 3 may b e o eratedfeither.

by a blast of air and steam 1n t 'e customary way, or better by a draftcurrent of airand products of combustion.

' generate and as its dissociation in the producer fire is incomplete,there is considerable loss in eiiiciency from the injection ofsteamInto' a producer in the quantity suiiicient to prevent clinker. On thecontrary products of combustion such as those obtained from the stack ofthe kiln after combustion has be-l come substantially complete, 'arelfree from the objectionable features of steam, and afford a uniformgas, without the production of clinker or slag 1n the producer.

The use of steam in a producer gives rise to hydrogen in the gas, thepresence of which seemingly decreases vthe content of -inert nitrogen;but my observations show me that readil gas passing therethrough intheh1gh"teniperatures demanded for theY Steam is costly to iicient to causethe passage to burn Wit eratur'e 1n excess of 2600 Fahrenheit, and

Y residue around the hydrogen' is not as suitable for the. production otemperature asis carbon monoxid. T 's is robably due to dissociationphenomena at high temperatures, which tend to prevent the perfectcombination of hydroen and oxygen.y While it is true that carbon .dioxiddissociates at high temperatures, and its degree of dissociation isdependent on its concentration, yet it is 'improbable that f itsdissociation proceeds to anything like the degree that `water .vapordoes, under the same conditions.` of attaining 'a' very hi'h temperaturein the clinkeringzone of theiln it follows that lthe operation` mustbesuch as to favor any conditionstending to increase the temperature;hence the importance which I place upon Ithe operation of the gasproducer with products o combustion.` The products of combustionemployed may be obtainedfrom any suitable source, althoughypreferably-from the kiln itself, owing to the lar e amount of carbondioXidpresent in the kiln gases." I' prefer to use these roducts ofcombustion at the highest ossib e temperature compatible with generaease of operation.4

Because ofthe necessity The v.heating stove 5 has been illustrated in apurely conventional way, but it must be understooo that it may beconstructed in. any

suitable mannerl with any number of i'lues," .eitlpr horizontally placedorotherwise, of sue design that the gas is" .quickly and efliclentlypreheated. 'Care should'be takenin the design of such a stoveto havethe-passages so arranged as to permit of their being y cleaned, andfurthermore `|ofl such size that the stove may be run for aconsiderable'period of time Without trouble arising from clogging due tothe-depositiorfl of the soot. l

y invention permits o the attainment of rapid production of cement,withutthe diffculties experienced'with suchfuel as poW- dered coal. f

I claim: 5 1

1. The recess of .heating rotary lcement kilns Which'consists ingenerating producer gas, passing the 'hotgasdirectlyT from. the

roducer through a passa e having walls'of eat conductingmaterialflieating said Walls by combustion therearound to an ententsuf1a iiame aving a temurningthe so-heated gas in a` rotary'cement kiln 1n'proximity to cement 'material ad' vanenli therethrough.

e process-of whlch consists in generating prd heating a portion o saidgas' by filiurnlng the ducer gas,

conduit thrugh which said portlon'tr'avels, removing the products ofcombustion of said residue as 'passin through said l heating cementkilns'- tion around sanare kilns which consists in generating producervgas substantially free of hydrogen, passing the hot gas directly tromthe gas produce through a passage having walls of heat conductingmateria nre-heating said walls to an extent suiicient to cause the gaspassing therepast to burn with a flame having a temperature in excess of2600 Fahrenheit, and

urning the so-heated gas in a rotary cement kiln in proximity .to cementmaterial passing therethrough.

4. The process of heating cement kilns which consists in generating dryproducer gas, heating a portion of said gas by burning the residuearound the conduit through which said portion travels, removing theproductsof combustion of said residue and finally' burnin the`heatedportion in a cement kiln.

5. T e process of heating rotary cement kilns which consists ingenerating producer gas, su perhe'ating the same by direct combusaheat-conductive conduitl containing the same, said superheating beingsufficiently intense to enable it to burn with a flame temperature inexcess of 2600 Fahrenheit, passin the superheated gas into. a rotarycement 'ln in the form of a jet and there burning it in proximity tocement material advancing therethrough by means of a jet of relativelycolder air introduced above and partly enveloping said jet ofsuperlieated gas.

6. A cement making apparatus comprising a gas producer, agas firedrotary cement kiln, a directly connecting gas conduit between producerand the burning means of the cement kiln, said conduithaving walls ofheat conducting material, and means for burning fuel around the conduitand in proximity to said walls.

7. A cement making apparatus comprising a gas producer, a gas ed kiln, agas conduit transmitting a portion of the producer gas to the burningmeans in the kiln, means for burning the residue of the gas around saidconduit to heat the portion of gas passing therethrou 'h, and means forremoving the products of combustion of said residue.

8. A cement making apparatus comprising a gas producer, a rotary cementkiln provided with gas burning means, said means comprising a jet inletfor gas and an arched air inlet communicating with a source of air underpressure and arranged immediately above said gas inlet, and a conduithaving Walls of heat-conducting material directly connecting theproducer and the gas inlet of the kiln,` said conduit being providedwith fire heating means externally of the same, wherebylthe hot gascoming from the producer may be superheated.

Signed at New York city in the county of New York and State of New Yorkthis 28th day of November, A. D. 1905.

HENRY L. DOHERTY.

Witnesses:

FLETCHER P. ScoFrELD, J. CEAS. ANDREWS.

